Dynamic structural analysis and physical testing performed to develop energy absorbing connectors used for supporting pre-cast reinforced concrete panels subjected to blast waves is summarized in “Blast Damage Mitigation Using Reinforced Concrete Panels and Energy Absorbing Connectors”, by Mark G. Whitney, prepared for the Department of Defense Explosive Safety Board 1996 Explosives Safety Seminar. The manuscript describes Energy Absorbing Units (EAUs) deployed behind concrete panels. Concrete panels are rigid (very high modulus) and consequently, the blast force is transferred directly from the concrete panels to the EAUs with little or no force dissipation provided by the concrete panels.
U.S. Pat. No. 3,933,386, issued to Fannin, describes a bumper assembly of a vehicle which is supported by a pair of energy absorber units each of which incorporates a piston assembly which strokes in an inner cylinder to force gas from an inner chamber to a gas spring chamber through an expansible and contractible control chamber controlled by one-way valves and bleed orifices. On the return stroke, compressed gas in the control chamber exerts a force opposing the gas spring return force exerted on the piston assembly. Gas in the control chamber meters through the bleed orifices into the inner chamber so that the return rate of the piston assembly is effectively controlled and reduced.
Taylor, in U.S. Pat. No. 4,031,978, discloses an energy absorber unit including a cylinder, liquid in the cylinder, a piston for movement into the cylinder for providing a liquid energy absorbing capability, and relatively movable parts associated with the cylinder and having frictional engagement for additionally providing a dry energy absorbing capability. Also disclosed is an energy absorbing unit including a tubular cylinder, a first tubular member slidable on the cylinder for carrying a force receiving member, and a second tubular member mounted on the first tubular member for mounting the first tubular member on a supporting member. An energy management system for a vehicle having a frame, an engine mounted on the frame and a bumper, including a first energy absorber unit mounted between the engine and the bumper and a plurality of second energy absorber units mounted between the bumper and the frame is further described.
U.S. Pat. No. 4,054,311, issued to Gute, provides an energy absorbing unit for a vehicle bumper support having inner and outer telescoping cylinders with primary valve for metering fluid between a pair of contractible and expansible fluid chambers to dissipate impact energy. An auxiliary pressure relief valve internal of the unit in parallel with the primary valve opens in response to predetermined pressure buildup in one of the chambers to control pressure and prevent damage to the unit. A gas spring in the unit moves the two cylinders in their extended position on removal of bumper impact load.
Petry, in U.S. Pat. No. 4,097,080, describes a pair of telescopic energy absorbers which are employed to mount a laterally extending bumper to the side rails of a vehicle frame. A mechanical interlock prevents relative rotation of the components of the energy absorbers so that the side rails are rigidly coupled by the bumper to increase their structural strength and to reduce vehicle shake.
U.S. Pat. No. 4,149,742, issued to Fannin et al., discloses an energy absorber incorporating a mounting bracket secured to a vehicle which by track and follower mechanism slidably mounts a support bracket that is secured to a vehicle bumper. One bracket supports a laterally extending energy absorbing band of resilient material engaged by the follower carried by the other bracket. On impact, the brackets telescope inwardly and an intermediate portion of the band is displaced by the follower to effect band deflection and energy absorption. On rebound, the band gradually restores to its original configuration to return the brackets and bumper to its pre-impact position.
Lura, in U.S. Pat. No. 4,178,028, provides an energy absorber yieldably coupling a bumper to a support structure on a vehicle and comprises a spring bracket assembly which includes a pair of diverging spring arms which carry pins on the ends thereof. A preloaded yieldable energy absorbing band of resilient plastic material is stretched across the arms, by attachment to the spaced pins. On impact of the bumper, the pins are displaced outwardly from one another as the spring arms are deflected to stretch the energy absorbing band. The deflection of the spring arms and the stretching of the energy absorber absorbs impact energy.
U.S. Pat. No. 4,830,418, issued to Gest, describes telescopic energy absorber units having outer tubes threaded into connection with vehicle hard bar bumper or fascia support to permit fore and aft adjustment by rotation of the piston tube of the unit in clockwise or counterclockwise direction.
Carlqvist in U.S. Pat. No. 5,003,832, discloses a motion transmitting mechanism for heat engines, refrigerating machines and heat pumps which are hermetically sealed or provided with rotary shaft seals and have reciprocating pistons connected to the motion transmitting mechanism by means of connecting rods, which is provided with two counter rotating crank systems which are centered along a single center line, whereby the lateral forces of the pistons counteract each other so as to be eliminated and allow the use of permanent grease-lubricated and sealed rolling bearings.
U.S. Pat. No. 5,823,705, issued to Jackson et al., provides a restraining barrier which is positionable across a roadway in a deployed position to define a restraining zone and may be moved vertically to a passive position by first and second transport components. Opposite ends of the barrier are coupled to the first and second transport components, respectively, and also couple the barrier to first and second energy absorbers of differing restraintive force in order stop vehicles of varying weight. A support cable is coupled to an indicator for providing a signal indicating vehicle impact. Additionally, a series of restraining barriers and energy absorbers may provide a series of sequentially differing restraintive forces to stop lightweight and heavier vehicles. The barrier of Jackson et al. may be a net and include a lower wire below the net assuring effective trapping of autos and trucks of a variety of heights.
Stewart et al., in U.S. Pat. No. 6,000,738, describe a vehicle bumper including a hollow tubular wall structure adapted to span the front or rear end of an automotive vehicle so as to absorb crash forces when the vehicle is involved in a crash situation at vehicle speeds above some predetermined speed level, e.g., five miles per hour. The hollow tubular wall structure includes an outer wall disposed to receive the crash force, an inner wall connectable to the vehicle, and four connector walls joining the outer wall to the inner wall. The four connector walls bend at a controlled rate to absorb crash energy. The outer and inner walls have aligned air openings adapted to conduct ram air to the vehicle radiator.
U.S. Pat. No. 6,554,530, issued to Moore, discloses an energy absorbing system to protect vehicle drivers and the like from serious injury which may occur when the vehicle strikes a wall or other rigid structure. The system utilizes a plurality of energy absorbing units having hinged plates with a cushion backing which dampens the impact by swinging in an overlapping fashion. The plates are formed from steel and the cushion is formed with a high density outer polymeric casing and relatively low density filler within.
Payne et al., in U.S. Pat. No. 6,814,246, provide a collision attenuating system for a moving vehicle including an energy-absorbing airbag assembly dimensioned and configured for attenuating the impact between the moving vehicle and a pedestrian or an impacted vehicle located in or crossing the path of the moving vehicle as the pedestrian or impacted vehicle impacts against the airbag assembly, a mounting bracket dimensioned and configured for being affixed to the moving vehicle, an engagement bracket affixed to the airbag assembly and engagable with the mounting bracket, and a quick-release fastener for removably engaging the engagement bracket to the mounting bracket for removably mounting the airbag assembly to the moving vehicle. The airbag assembly includes an airbag and an assembly frame supporting the airbag, a speed sensor for determining the speed of the vehicle, and a pressure regulator for controlling a pressure function of the airbag responsive to the speed sensor. The airbag assembly includes an upper deflatable airbag, and a lower pedestrian support, the pedestrian support including energy-absorbing structure. Payne et al. also provide a method of using the collision attenuating system.
U.S. Pat. Nos. 7,360,822, 7,404,593 and 7,625,023 describe a modular energy absorber that is tunable. It comprises one or more energy absorbing modules. The energy absorbing modules have means for coordinating energy absorbing units of the one or more modules. The means for coordinating position and support the units in relation to each other before, during and after relative motion between an incident object and the energy absorber. A crushable member is provided that has an upper perimeter, a lower perimeter and an intermediate section extending therebetween. It also includes a number (m) of breaches defined therein before impact. A method for configuring the modular energy absorber is also described.
Cormier et al., in U.S. Pat. No. 7,625,036, describes a multi-sectional, modular energy absorber comprising one or more modules, which have one or more energy absorbing units. Some have a first section and a second section that are united like a clamshell to form the energy absorbing unit. There is a means for locating the sections in relation to each other. First and second flange sections extend from at least some of the first and second sections. There are means for coordinating energy absorbing units in one of the one or more modules, the means for coordinating having a topography including a number (n) of apertures defined therein, where n is an integer ≧0. At least some of the sections include an upper perimeter, a lower perimeter and an intermediate wall extending therebetween with a number (m) of breaches defined in the intermediate wall before impact, where m is an integer ≧0.
U.S. Pat. No. 7,628,444, issued to Cormier et al., discloses a multi-sectional, modular energy absorber comprising one or more modules, which have one or more energy absorbing units. Some have a first section and a second section in some embodiments that are united like a clamshell to form the energy absorbing unit. There is a means for locating the sections in relation to each other. First and second flange sections extend from at least some of the first and second sections. There are means for coordinating energy absorbing units in one of the one or more modules, the means for coordinating having a topography including a number (n) of apertures defined therein, where n is an integer ≧0. At least some of the sections include an upper perimeter, a lower perimeter and an intermediate wall extending therebetween with a number (m) of breaches defined in the intermediate wall before impact, where m is an integer ≧0. When positioned over an underlying elongate support member, the energy absorption characteristics at the distal ends of the absorber differ from those at its central region.
Gansweidt in U.S. Pat. No. 7,735,427, provides a shock absorber for use as an additional irreversible shock-absorbing stage together with a component for transferring force. To achieve the reliable dissipating of high impact energies, Gansweidt provides a shock absorber comprising: a base plate; a force-transferring element having a tensioning element; an energy-absorbing element in the form of a deformation tube which is connected by a first end section to the base plate; and a connecting element for the disengageable connecting of the force-transferring element to a second end section of the deformation tube, wherein the connecting element is pressed against the tensioning element such that the deformation tube is braced between the tensioning element and the base plate without play.
Statutory Invention Registration No. H2,229, provides an apparatus for mitigating the effects of shock loading on occupants, cargo and gear the apparatus located in a watercraft the apparatus having a deck positioned and arranged in the watercraft for supporting thereon the occupants, cargo and gear, a hinge communicating with the deck and the watercraft and supporting the forwardly portion of the deck and permitting the deck to move and rotate about the hinge and prevent the deck from substantial side to side movement, a dampener communicating with the deck and hull of the watercraft the dampener positioned and arranged to move in response to the moving and rotating deck and the dampener absorbing at least a portion of the energy of the moving deck as the deck moves and rotates, and a spring communicating with the deck and the hull of the watercraft the spring positioned and arranged to support the rearwardly portion on the deck and to move in response to the moving and rotating deck the spring absorbing at least a portion of the energy of the moving and rotating deck and releasing the absorbed energy to raise the deck after the impacts.
U.S. Patent Application Publication No. 2010/0101404 A1 in the name of Lorenzo et al. describes a bi-active method of mounting a monolithic polycarbonate sheet or a laminate in a semi-rigid metallic framing system along two parallel sides of a rectangular shaped sheet or laminate with the two shorter parallel sides being unconstrained. In the case of a square shaped sheet, two parallel sides are supported in the semi-rigid frame, and the other two parallel sides are unconstrained. The semi-rigid frame utilizes cylindrically shaped hardware (i.e., bolts, rivets, studs, etc.) to hold the sheet or laminate. The semi-rigid frame is designed, via section and material properties, to flex and hinge about fixed mounting points along the length of the frame.
Pyles et al., in U.S. Patent Application Publication No. 2011/0048219 A1 disclose a blast-resistant barrier comprising a plurality of units each including a panel having a thickness of greater than 20 to less than 40 millimeter. The panel is in the form of a monolithic polycarbonate sheet or laminate that is positioned vertically between the source of a blast and the blast target, the laminate including at least two polycarbonate sheets and an optional image layer interposed therebetween. The panel is fixedly attached to a frame which is firmly embedded in concrete in a manner calculated to provide stiffness sufficient to absorb and withstand external forces resulting from said blast. In a preferred embodiment the panel includes at least two polycarbonate sheets laminated one to the other, optionally including an image layer interposed therebetween. In an additional embodiment, the frame is anchored securely to the target enabling dissipation of the blast force through the target's structure. The height of the blast-resistant barrier is preferably proportional to the height of the target.
U.S. Pat. No. 8,347,775 issued to Altenhof et al., provides an energy dissipation assembly for mounting between a fixed support and moveable support. The assembly includes a sacrificial deformation tube, a hardened cutter/deflector assembly and, optionally, a connecting cable to maintain the cutter/deflector assembly in juxtaposed coaxial alignment with an end deformation tube. The cutter/deflector assembly has a generally flattened disc shaped profile and includes a central hub, a circular support ring and one or more cutting blades. The support ring is concentrically about the hub and has an inner diameter greater than the outer tube diameter. On the occurrence of a shock force, the cutter/deflector assembly moves axial to cut/deform the deformation tube to dissipate force energy.
A need continues to exist in the art for improvements to blast barrier systems to provide increased blast resistance to further minimize damage to people and structures.